1. Field of the Invention
The present invention is directed to a liquid metal plain bearing of the type having a rotating and a stationary bearing part, between which a bearing gap filled with liquid metal is located.
2. Description of the Prior Art
It is undesirable for liquid metal plain bearings of the above type to lose liquid metal, because the liquid metal is generally a highly reactive substance. As a rule, gallium, indium or tin alloys, which are already liquid at room temperature, are used as liquid metals. Liquid metal plain bearings are used, for example, in x-ray tubes in order to provide the rotating anode with bearings (see e.g. German OS 28 52 908, European Application 0 479 197 or U.S. Pat. No. 5,195,119), and are thereby normally housed in the interior of the vacuum housing of the x-ray tube. Liquid metal emerging from the liquid metal plain bearing is particularly harmful in for the case of x-ray tubes, because drops of liquid metal can endanger the high-voltage strength of the x-ray tube when they leave the area of the anode.
An x-ray tube known from European Application 0 373 705, has a rotating anode provided with bearings in the form of a liquid metal plain bearing. The rotor of an electromotor drives the rotating anode, and a carrier body serves for mounting of the stationary bearing part, are both thus provided with a coating of material, namely gold, that binds reactively to the liquid metal. The danger that liquid metal emerging from the liquid metal plain bearing will leave the anode area and endanger the high-voltage strength of the x-ray tube is thus reduced.